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Selective Aryl a-Diimine/Palladium-Catalyzed Bis-Alkoxycarbonylation
was injected in a nitrogen-flushed autoclave, equipped with
a magnetic stirring bar, containing benzoquinone (325 mg,
3 mmol) and p-TSA·H2O (7.6 mg, 0.04 mmol) in MeOH
(3.5 mL). After 10 min of stirring, the respective olefin 2a–o
(2 mmol) was added in one portion into the reaction mix-
ture. The autoclave was flushed three times with CO and
pressurized to 4 bar of carbon monoxide. The reaction mix-
ture was vigorously stirred at the room temperature (208C)
for 66 h. The autoclave was vented off, flushed with nitrogen
173.3, 51.9, 51.4, 51.3, 32.7, 27.9; ESI-MS: m/z=203 [M+
H]+.
Diisopropyl 2-phenylsuccinate (3n): Following the general
procedure, but performing the reaction with 2 mol% catalyst
loading [13.3 mg, 0.04 mmol of Pd(TFA)2 and 19.2 mg,
0.044 mmol of 1i] and using i-PrOH as the alcohol, com-
pound 3n was obtained as a colorless oil; yield: 92%.
1H NMR: d=7.26 (br s, 5H), 4.98 (hept, J=6.3 Hz, 1H),
4.97 (hept, J=6.2 Hz, 1H), 4.01 (dd, J=5.5, 10.2 Hz, 1H),
3.12 (dd, J=10.2, 16.7 Hz, 1H), 2.60 (dd, J=5.5, 16.7 Hz,
1H), 1.22 (d, J=6.3 Hz, 3H), 1.19 (d, J=6.2 Hz, 3H), 1.16
(d, J=6.2 Hz, 3H), 1.08 (d, J=6.3 Hz, 3H); 13C NMR: d=
172.4, 171.0, 138.0, 128.7, 127.7, 127.4, 68.4, 68.1, 47.5, 38.2,
21.7, 21.7, 21.4; ESI-MS: m/z=278 [M+H]+.
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and the reaction mixture was directly analyzed by H NMR
to determine the conversion and the ratio of the products 3
and 4. The crude material was then dried under reduced
pressure and filtered through a plug of silica gel, washing
with CH2Cl2/Et2O 8:2 (25 mL) and finally the solution was
evaporated under vacuum. The product was eventually ob-
tained after column chromatography on silica gel (petrole-
um ether/CH2Cl2 50:50 then 30:70).
Dibenzyl 2-phenylsuccinate (3o): Following the general
procedure, but performing the reaction with 2 mol% catalyst
loading [13.3 mg, 0.04 mmol of Pd(TFA)2 and 19.2 mg,
0.044 mmol of 1i] and using BnOH as the alcohol, com-
pound 3o was obtained as a colorless oil; yield: 94%.
1H NMR: d=7.51–7.09 (m, 15H), 5.10 (br s, 4H), 4.18 (dd,
J=9.9, 5.5 Hz, 1H), 3.29 (dd, J=16.9, 10.0 Hz, 1H), 2.77
(dd, J=16.9, 5.5 Hz, 1H); 13C NMR: d=172.7, 171.3, 137.5,
135.8, 135.7, 128.9, 128.6, 128.50, 128.33, 128.28, 128.2, 127.9,
127.8, 66.8, 66.7, 47.4, 37.8; ESI-MS: m/z=375 [M+H]+.
(2R*,3R*)-Dimethyl 2-methyl-3-phenylsuccinate (3p):
Following the general procedure, but performing the reac-
tion with 2 mol% of catalyst loading [13.3 mg, 0.04 mmol of
Pd(TFA)2 and 19.2 mg, 0.044 mmol of 1i], compound 3p was
Dimethyl 2-(2-chlorophenyl)succinate (3g): Following the
general procedure, compound 3g was obtained as a pale
yellow oil; yield: 94% (over a conversion of 75% of 2-chlor-
ostyrene 2g, determined by 1H NMR analysis on a direct
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sample of the reaction mixture). H NMR: d=7.47–7.13 (m,
4H), 4.60 (dd, J=9.8, 5.1 Hz, 1H), 3.67 (s, 3H), 3.66 (s,
3H), 3.13 (dd, J=17.0, 9.8 Hz, 1H), 2.65 (dd, J=17.0,
5.1 Hz, 1H); 13C NMR: d=172.9, 171.7, 135.6, 133.6, 130.0,
128.9, 128.8, 127.3, 52.4, 51.9, 44.0, 36.4; ESI-MS: m/z=257
[M+H]+.
Dimethyl 2-(2-bromophenyl)succinate (3h): Following the
general procedure, compound 3h was obtained as a pale
yellow oil; yield: 91% (over a conversion of 45% of 2-bro-
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obtained as a pale yellow wax; yield: 92%. H NMR: d=
7.36–7.21 (m, 5H), 3.81 (d, J=10.9 Hz, 1H), 3.65 (s, 3H),
3.40 (s, 3H), 3.24 (dq, J=10.9, 6.8 Hz, 1H), 1.28 (d, J=
6.8 Hz, 3H); 13C NMR: d=174.3, 172.5, 136.6, 128.4, 128.1,
127.6, 54.6, 51.9, 51.3, 43.6, 16.2; ESI-MS: m/z=237 [M+
H]+.
(2S*,3R*)-Dimethyl 2-methyl-3-phenylsuccinate (3q): Fol-
lowing the general procedure, but performing the reaction
with 2 mol% of catalyst loading [13.3 mg, 0.04 mmol of
Pd(TFA)2 and 19.2 mg, 0.044 mmol of 1i], compound 3q was
obtained as a pale yellow oil; yield: 87%. 1H NMR: d=
7.44–7.25 (m, 5H), 3.81 (d, J=11.4 Hz, 1H), 3.77 (s, 3H),
3.67 (s, 3H), 3.21 (dq, J=11.3, 7.3 Hz, 1H), 0.99 (d, J=
7.3 Hz, 3H); 13C NMR: d=176.0, 173.6, 136.2, 128.8, 128.3,
127.7, 54.1, 52.0, 51.9, 42.2, 15.3; ESI-MS: m/z=237 [M+
H]+.
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mostyrene 2h, determined by H NMR analysis on a direct
1
sample of the reaction mixture). H NMR: d=7.61–7.54 (m,
1H), 7.30–7.21 (m, 2H), 7.18–7.07 (m, 1H), 4.63 (dd, J=
10.0, 4.9 Hz, 1H), 3.66 (s, 3H), 3.64 (s, 3H), 3.12 (dd, J=
17.0, 10.0 Hz, 1H), 2.68 (dd, J=17.0, 5.0 Hz, 1H);
13C NMR: d=172.9, 171.7, 137.4, 133.4, 129.1, 128.8, 128.0,
124.3, 52.5, 52.0, 46.4, 36.7; ESI-MS: m/z=301 [M+H]+.
Dimethyl 2-(3-(trifluoromethyl)phenyl)succinate (3i): Fol-
lowing the general procedure, compound 3i was obtained as
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a colorless oil; yield: 85%. H NMR: d=7.59–7.40 (m, 4H),
4.15 (dd, J=5.5 Hz, 9.8 Hz, 1H), 3.66 (s, 3H), 3.64 (s, 3H),
3.21 (dd, J=9.7, 17.0 Hz, 1H), 3.21 (dd, J=5.5, 17.0 Hz,
1H); 13C NMR: d=172.8, 171.6, 138.7, 131.30 (q, J=
1.1 Hz), 131.28 (q, J=32.4 Hz), 129.5, 124.74 (q, J=3.7 Hz),
124.69 (q, J=3.7 Hz), 124.0 (q, J=272.4 Hz), 52.6, 52.0, 46.9,
37.4; ESI-MS: m/z=291 [M+H]+.
Dimethyl 2-pentylsuccinate (3k): Following the general
procedure, but performing the reaction with 1 mol% catalyst
loading [6.6 mg, 0.02 mmol of Pd(TFA)2 and 9.6 mg,
0.022 mmol of 1i] compound 3k was obtained as a colorless
oil; yield: 92%. 1H NMR: d=3.70 (s, 3H), 3.68 (s, 3H),
2.93–2.64 (m, 2H), 2.44 (dd, J=15.9, 4.6 Hz, 1H), 1.72–1.43
(m, 2H) 1.39–1.13 (m, 6H), 0.97–0.79 (m, 3H); 13C NMR:
d=175.7, 172.7, 51.8, 51.7, 41.1, 35.7, 31.8, 31.4, 26.5, 22.3,
13.9; ESI-MS: m/z=217 [M+H]+.
Acknowledgements
This work was supported by Ministero dell’Universitꢀ e della
Ricerca (PRIN n. 2008A7P7YJ).
References
[1] For recent reviews, see: a) X.-F. Wu, H. Neumann, M.
Beller, ChemSusChem 2013, 6, 229; b) X.-F. Wu, H.
Neumann, M. Beller, Chem. Rev. 2013, 113, 1; c) B. Ga-
briele, R. Mancuso, G. Salerno, Eur. J. Org. Chem.
2012, 6825; d) Q. Liu, H. Zhang, A. Lei, Angew. Chem.
2011, 123, 10978; Angew. Chem. Int. Ed. 2011, 50,
10788; e) J. Liu, J. Chen, W. Sun, C. Xia, Chin. J. Catal.
2010, 31, 1; f) A. Brennfuehrer, H. Neumann, M.
Dimethyl 2-tert-butylsuccinate (3m): Following the gener-
al procedure, but performing the reaction with 2 mol% of
catalyst loading [13.3 mg, 0.04 mmol of Pd(TFA)2 and
19.2 mg, 0.044 mmol of 1i], compound 3m was obtained as
a pale yellow oil; yield: 95% (over a conversion of 53% of
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3,3-methyl-1-butene 2m). H NMR: d=3.66 (s, 3H), 3.63 (s,
3H), 2.85–2.39 (m, 3H), 0.93 (s, 9H); 13C NMR: d=174.8,
Adv. Synth. Catal. 0000, 000, 0 – 0
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